JPS6218469A - Polyphenylene ether resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent moldability and resistance to solvents, heat and impact, by blending a polyphenylene ether with a styrene resin composed of two polymers having higher and lower average MW. CONSTITUTION:95-4wt% polyphenylene ether (A) having an intrinsic viscosity of 0.2-1dl/g (in CHCl3 at 30 deg.C) obtd. by copolymerizing 2,6-di-methylphenol, etc. and 2,3,6-trimethylphenol, etc. is blended with 5-95wt% styrene resin (B) composed of a mixture having a weight-average MW of 32X10<4> or below and a toluene-soluble matter content of 93-3wt%, consisting of 5-95wt% polymer having a weight-average MW of 7X10<4>-18X10<4> and 95-5wt% polymer having a weight-average MW of 20X10<4> or above, said polymers containing 2-50wt% graft rubber (a) and/or non-graft rubber (b) obtd. by polymerizing a monomer component mainly composed of an arom. vinyl compd. in the presence of absence of a rubbery polymer such as an ethylene/alpha-olefin/polyene terpolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Industrial Application Field The present invention relates to a polyphenylene ether thermoplastic resin composition having excellent impact resistance, solvent resistance, heat resistance, and moldability.

b. Prior Art Polyphenylene ether resin is widely known as a resin with excellent heat resistance, mechanical properties, and electrical properties. However, this polyphenylene ether has drawbacks such as low impact resistance, poor processability, and thermal discoloration and gelation at high temperatures, so it is rarely used alone and is usually ) It is used as a modified polyphenylene ether resin consisting of a composition of polystyrene and rubber-modified polystyrene. This modified polyphenylene-ether resin has excellent heat resistance, mechanical properties, electrical properties, processability, etc., and is therefore widely used in automobile parts, office equipment, electrical appliance parts, and the like.

Problems to be Solved by the C0 Invention However, the rubber-modified polystyrene is usually obtained by dissolving a rubbery polymer in styrene monomer and then performing bulk-suspension polymerization. To achieve this advantage, it is necessary to limit the amount of rubbery polymer used, usually about 10
Less than % by weight is used. Therefore, such a composition of rubber-modified polystyrene and polyphenylene ether does not have sufficient impact resistance. Further, this composition has a drawback that it has poor solvent resistance and is easily cracked by, for example, kerosene, gasoline, and the like. In order to improve these drawbacks, a method of using polystyrene with a high intrinsic viscosity [η] has been proposed, as seen in JP-A-48-42047, but such a composition has poor moldability. It had the disadvantage of being significantly inferior.

The inventors of the present invention have conducted extensive studies on polyphenylene ether resin compositions that have excellent impact resistance, solvent resistance, heat resistance, and moldability. 10' and a polymer with a weight average molecular weight of 20 x 10' or more, and the weight average molecular weight of the mixture is 32 x 10
A polyphenylene ether resin composition containing the following styrene polymers has the following properties:
It has been found that solvent resistance and moldability are improved, and the present invention has been achieved based on these findings.

d. A means for solving the problem, that is, the present invention, is a grafted rubber (a') grafted with a monomer mainly containing an aromatic vinyl compound (al polyphenylene ether fbl) and/or a non-grafted rubber (b' ), wherein (a) the toluene-soluble portion of the styrene resin fbl (
Weight average molecule of a') 117 x 104 to 18 x 10
' polymer 5-95% by weight and weight average molecular weight 20x
104 or higher, and the weight average molecular weight of the mixture is 32 x 10' or less, and (b) the content of the polyphenylene ether (a) in the composition is 95-5% by weight, (a') and (b'
) The total content of (a') is 2 to 50% by weight, and the content of (a') is 93 to 3% by weight.

The polyphenylene ether used in the present invention, which will be described in detail below, is obtained by oxidative coupling polymerization of one or more ferrule compounds represented by the general formula in the presence of a known catalyst.

Particularly preferred among the ferrule compounds are phenol compounds represented by the general formula %, and specific examples of the most preferred phenol compounds include 2.6-dimethylphenol, 2.6-ethylphenol, 2-methyl-6
-Ethylphenol, 2-methyl-6-allylphenol 1,2-methyl-6-phenylphenol, 216-
diphenylphenol, 2,6-sibutylphenol,
2-Methyl-6-propylphenol, 2゜3.6-drimethylphenol, 2,3-dimethyl-6-ethylphenol, 2,3.6-driethylphenol, 2,3
．． Examples include 6-1-liprobylphenol, 2,6-dimethyl-3-ethylphenol, and 2,6-dimethyl-3-propylphenol.

Specific examples of the most preferred polyphenylene ethers include polyphenylene ether obtained from 2,6-dimethylphenol and polyphenylene ether obtained from 2,6-dimethylphenol and 2.
．． 3.6-) Polyphenylene ether obtained by copolymerization of trimethylphenol. Especially 2,3.6-
Copolymerized polyphenylene ether obtained from trimethylphenol and 2,6-dimethylphenol has heat resistance,
Good impact resistance, molded product surface gloss, moldability, solvent resistance, and thermal stability.

Intrinsic viscosity of polyphenylene ether used in the present invention [
η] (measured at 30° C. in chloroform) is not particularly limited, but is preferably 0.2 to 1j/g, more preferably 0.25 to 0.4 dl/g. The blending amount of polyphenylene ether in the polyphenylene ether resin composition of the present invention is 95 to 5% by weight, preferably 60-10% by weight.
% by weight, more preferably 60 to 20% by weight. When the amount of polyphenylene ether is less than 5% by weight, no remarkable effect on improving heat resistance is observed, and when the amount exceeds 95% by weight, no effect on improving impact resistance is observed.

The styrenic resin fbl of the present invention is obtained by polymerizing a monomer containing an aromatic vinyl compound as a main component in the presence or absence of a rubbery polymer.

The rubbery polymers used include ethylene-α-olefin copolymer, ethylene-α-olefin-polyene terpolymer, polybutadiene, styrene-butadiene random copolymer, pro-copolymer, and butadiene. - Diene rubbers such as isoprene copolymers, acrylic rubbers, etc.

The above ethylene-α-olefin copolymer, ethylene-α
- The α-olefin of the olefin-polyene terpolymer is a hydrocarbon compound having 3 to 20 carbon atoms,
Specific examples include propylene, butene-1, pentene-1,
11hexene-1,heptene-1,4-methylbutene-
Examples include 1,4-methylpentene-1, styrene, P-isopropylstyrene, and vinylcyclohexane, with propylene being particularly preferred. In addition, the above polyene compounds include 1,4-pentadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene, 3.3-hexadiene,
-dimethyl-1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 6-methyl-1°5-hexadiene, 1,4-hexadiene, 7-methyl-1,6
-Octadiene, 9-methyl-1,9-undecane, isoprene, 1,3-pentadiene, 1,4,9-decatriene, 4-vinyl-1-cyclohexane, cyclopentadiene, 2-methyl-2,5-norbornadiene , 5
-methylene-2-norbornene, 5-ethylidene-2-
Examples include norbornene, 5-isopropylidene-2-norbornene, 5-isopropenyl-2-norbornene, dicyclopentadiene, tricyclopentadiene, and the like. The acrylic rubber is a polymer obtained from one or more monomers selected from (meth)acrylic acid alkyl esters having an alkyl group having 2 to 12 carbon atoms. Examples include esters of (meth)acrylic acid such as ethyl, butyl, hexyl, octyl, 2-ethylhexyl, and lauryl. In some cases, monomers copolymerizable with acrylic acid alkyl esters are used. These monomers include ethylenically unsaturated monomers such as acrylonitrile, vinyltoluene, styrene, α-methylstyrene, and P-methylstyrene, and conjugates of butadiene, isoprene, 2,3-dimethylbutadiene, piperylene, chloroprene, etc. Examples include diene monomers and the aforementioned polyene compounds.

These monomers can be used alone or in combination of two or more. The preferred ratio of the other copolymerizable monomer to the alkyl ester of (meth)acrylic acid is 100 to 50% by weight of the former and 0 to 50% by weight of the latter. The above rubber components can be used alone or in combination of two or more.

As the rubbery polymer used in the present invention, a rubber supply body (a') grafted with a styrene polymer may be used, or a rubber supply body (a') without grafting may be used. When a grafted polymer is used, preferred rubbery polymers are styrene, butadiene copolymer, polybutadiene, ethylene-propylene copolymer, and ethylene-propylene-polyene terpolymer. Non-grafted rubbery polymer (b'
), preferred rubbery polymers are polystyrene-polybutadiene block copolymers, polystyrene-polybutadiene-polystyrene block copolymers, radial teleblock copolymers thereof, and hydrogenated products thereof.

The rubbery polymer (a') contains a styrene-based polymer grafted when a styrene-based polymer is graft-polymerized in the presence of a rubbery polymer.

Aromatic vinyl compounds used in the present invention include styrene, α-methylstyrene, methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, motsupromustyrene, dibromustyrene, P-tert-butylstyrene, ethylstyrene, Examples include vinylnaphthalene, and styrene is particularly preferred. Moreover, these can be used alone or in combination of two or more. Further, depending on the use, other vinyl monomers that can be copolymerized with the above-mentioned aromatic vinyl compound can also be copolymerized. Other vinyl monomers copolymerizable with the aromatic vinyl compound include vinyl cyanide compounds, alkyl acrylates, alkyl methacrylates, unsaturated acid anhydrides, unsaturated acids, and maleimide compounds. These may be used alone or in combination of two or more.

Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile.

Examples of acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, Examples include benzyl acrylate.

Examples of methacrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate,
Examples include octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, and benzyl methacrylate.

Examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like.

Examples of maleimide compounds include phenylmaleimide.

The amount of other vinyl monomers that can be copolymerized with these aromatic vinyl compounds is preferably 10% by weight or less in the styrenic polymer from the viewpoint of compatibility.

In order to obtain a composition with excellent impact resistance, solvent resistance, heat resistance, and moldability, which is the object of the present invention, it is necessary to Consisting of a combination (■) and a polymer (■), the weight average molecular weight of the polymer (■) is 7×1
04~18×104, preferably 10×10'~
18 x 104, more preferably 10 x 10'~
16 x 10', and the weight average molecular weight of polymer (1) is 20 x 10' or more, preferably 20 x 104 -
75 x 104, more preferably 20 x 10'~6
It is 8×104. In addition, in the present invention, the molecular weight is TI
It was measured at room temperature by GPC using IF as a solvent. In addition, the intrinsic viscosity (measured in toluene solution at 30°C) [η] of polymer (1) is preferably 0.4 to 0.65 d1/g,
More preferably 0.45 to 0.65 d! /g.

Further, [η] of the polymer (1) is preferably 0.15 a/g or more, more preferably 0.75 to 2.0 a/g, particularly preferably 0.75 to 1.8 a/g. Katsuno (
c') is ■/■=95-515-95% by weight, preferably 95-1015-90, more preferably 90-20
/ It is necessary to use a mixture in the range of 80 to 10. If the above average molecular weight is less than 7×10 4 , solvent resistance and impact resistance will be poor. Furthermore, if the average molecular weight exceeds 18 x 10', processability will be poor. Furthermore, if the amount used exceeds 95% by weight, the solvent resistance will be poor. If it is less than 5% by weight, processability will be poor. If the average molecular weight of the above item (2) is less than 20 x 10', there is no effect of improving solvent resistance. Further, if the amount used is less than 5% by weight, there is no effect of improving solvent resistance and impact resistance. If it exceeds 95% by weight, processability will be significantly reduced. Further, the weight average molecule ff of the mixture of the above polymers (1) and (2), i.e., (c') is 132 x to' or less, preferably 31 x 10' to 14 x 104, more preferably 29 x 10' to 14 x 10'. . Further, [η] of the mixture (c') is 1. Preferably less than Oa/g, more preferably 0.95 to 0.50 d
I/g. If the average molecular weight is 32 x 10' or more, processability is poor.

The content of the above component in the polyphenylene ether resin composition of the present invention is 5 to 95% by weight, preferably 40 to 95% by weight.
It is preferably 90% by weight, preferably 40 to 80% by weight. The content of (a') and (b') in the polyphenylene ether resin composition of the present invention is 2 to 50% by weight, preferably 5 to 30% by weight, more preferably 5 to 30% by weight.
It is 20% by weight. If it is less than 2% by weight, impact resistance will be poor;
If it exceeds 50% by weight, moldability will be poor.

Furthermore, in the polyphenylene ether resin composition of the present invention (
The content of c') is 93-3% by weight, preferably 8
It is 5 to 30% by weight, more preferably 80 to 30% by weight. If it exceeds 93% by weight, heat resistance and impact resistance will decrease, and if it is less than 3% by weight, processability will be poor.

The particle diameter of the rubber dispersed in the polyphenylene ether resin composition of the present invention is preferably 0.05 to 5 μm. Particularly when the rubber particle size is in the range of 0.05 to 0.5μ, when the polyphenylene ether resin composition is injection molded to obtain a molded product, the molded product is removed by ejecting pins when taking out the molded product from the mold. If whitening marks appear on the surface, a good molded product can be obtained. In addition, within this range of rubber particle size, the surface gloss of the molded product will be good. Moreover, when the rubber particle size is in the range of 1.5 to 3 μm, the solvent resistance and heat deterioration resistance are good.

The particle size of the rubber dispersed in the polyphenylene ether resin can be measured from an electron micrograph.

Furthermore, a copolymer of a vinyl cyanide compound such as acrylonitrile and an aromatic vinyl compound such as styrene, the rubbery polymer having a composition distribution AS in which the content of bound vinyl cyanide has a wide composition distribution; Preferably 5 to 30% by weight, more preferably 5 to 2% by weight of the modified polyphenylene ether resin composition of the present invention.
By blending within the range of 0% by weight, even better impact resistance, solvent resistance, paintability, and plating performance can be obtained. The above composition distribution AS can be produced by appropriately changing the amounts of aromatic vinyl and vinyl cyanide during polymerization.

Here, the composition distribution AS means that the copolymer composition is a mixture of copolymers with different amounts of bonded vinyl cyanide compounds, and the composition is such that (A) the content of vinyl cyanide compounds is 1
The content of the polymer component having a composition of at least 10% by weight and less than 10% by weight is 1 to 50% by weight, preferably 5 to 30% by weight.
and (B) the content of the polymer component having a composition in which the vinyl cyanide compound content is 10% by weight or more and less than 20% by weight is 1 to 70% by weight, preferably 5 to 70% by weight, more preferably is 10 to 50% by weight, and the content of (c) a polymer component having a composition in which the content of vinyl cyanide compound is 20% by weight or more and less than 40% by weight is 5 to 90% by weight, preferably 10 to 50% by weight. 80% by weight, more preferably 20%
~80% by weight, and the content of the polymer component having a composition in which the content of (D) vinyl cyanide compound is 40% by weight or more is 0 to 7.
0% by weight, preferably 0 to 20% by weight, and more preferably no content. The content of the vinyl cyanide compound in the copolymer composition is 10 to 40% by weight, preferably 15 to 35% by weight, more preferably 1% by weight.
It is 5 to 30% by weight, particularly preferably 20 to 28% by weight.

As a method for measuring the composition distribution in the above-mentioned copolymer, for example, the method described in Polymer Journal Vol 6, I'
It can be measured by the method described in H6.532-536 (1974).

The styrenic polymer used in the present invention can be produced by known polymerization methods such as emulsion polymerization, solution polymerization, bulk polymerization, and suspension polymerization. For the purpose of changing the average molecular weight of the polymer, a polymer having the desired average molecular weight can be obtained by appropriately changing the method of adding monomers, the amount of polymerization catalyst, the amount of chain transfer agent, etc. All known auxiliary raw materials such as emulsifiers, polymerization catalysts, chain transfer agents, and suspending agents used in the production of styrenic polymers can be used.

The composition of the present invention comprises a solution blend of each component of the above composition,
It can be obtained by mixing using a kneading extruder, Banbury, kneader, etc.

The polyphenylene ether resin composition of the present invention can be used to obtain various molded products by injection molding, sheet extrusion, vacuum molding, irregular molding, foam molding, and the like.

When using the polyphenylene ether resin of the present invention, commonly used antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents, blowing agents, glass fibers, etc. can be added.

Particularly preferred antioxidants are phosphorus-based antioxidants, and preferred flame retardants are triphenyl phosphate,
It is a phosphorus-based flame retardant represented by tri(noryl phenyl) phosphate.

Moreover, the polyphenylene ether resin composition of the present invention is
Furthermore, other known polymers may be used depending on the required performance, such as polypropylene, polyethylene, polyvinyl chloride, polycarbonate, PETSPBT, polyamide, epoxy resin, polyhynylidene fluoride, polysulfone, ethylene-vinyl acetate copolymer, PPS resin, It may be used by appropriately blending it with polyether ethyl ketone or the like.

e. Examples Next, the present invention will be explained in more detail with reference to Production Examples and Examples, but these are merely illustrative and do not limit the content of the present invention. Note that parts and % on each side below indicate parts by weight and % by weight, respectively.

The average molecular weight of the polymer was determined by GPC at room temperature using THF as a solvent.

Production Examples Polyphenylene ether used in Examples and Comparative Examples was obtained by the following method.

Production of Polymer-A-1 (Polyphenylene Ether) After purging the inside of a stainless steel reaction vessel equipped with an oxygen blower, a cooling coil, and a stirrer at the bottom of the reactor with nitrogen, 53.6 g of cupric bromide, Di-n-butylamine 111Q
g, further add 2,6-xylenol 8 to toluene 4ON
After 7.5 g of the solution was dissolved and added and stirred to make a homogeneous solution, polymerization was carried out for 90 minutes while rapidly blowing oxygen into the reaction vessel. During the polymerization, water was circulated through a cooling coil to maintain the internal temperature at 30°C. After polymerization,
30 n of toluene was added, and a 20% aqueous solution of 430 g of trisodium ethylenedi7minetetraacetate dissolved in water was added to stop the reaction.

The polymer solution phase was removed by centrifugation.

While vigorously stirring the polymer solution phase, methanol was gradually added to form a slurry. After being furnace-separated, the polymer was thoroughly washed with methanol, further furnace-separated, and then dried to obtain Polymer A-1.

Production of Polymer A-2 (Polyphenylene Ether) The phenol compound used in the production method of Polymer A-1 was
．． Polymers A to 2 were obtained in place of 6-xylenol/2,3°6-trimethylphenol=90/10 (molar ratio).

Production of rubber-modified styrenic polymer (B-1) After sufficiently purging the inside of a stainless steel reaction vessel with a stirrer with nitrogen, 4000 g of diene rubber latex (refined yarn 0623μ) was added (
solid content), sodium dodecylbenzenesulfonate 130g
After adding 12 g of potassium hydroxide, 2500 g of styrene and 1400 g of ion-exchanged water, the mixture was thoroughly stirred and heated while circulating hot water at 70'C in the jacket. Internal temperature is 5
When the temperature reaches 0°C, add 950 g of ion exchange water, 20 g of sodium pyrophosphate, 25 g of glucose, and 0.4 g of ferrous sulfate.
and cumene hydroperoxide 2
After adding 5.2 g of styrene and carrying out a polymerization reaction for 2 hours, 3500 g of styrene, 170 g of sodium dodecylbenzenesulfonate, 18 g of potassium hydroxide, and 500 g of ion-exchanged water were added.
An emulsion containing 25.2 g of cumene hydroperoxide was continuously added and polymerized for 3 hours.

After adding the emulsion, add 6.7 g of sodium pyrophosphate, 8.3 g of glucose, 0.13 g of ferrous sulfate, and 3 g of ion-exchanged water.
After adding 17 g of an aqueous solution and 7 g of cumene hydroperoxide, the polymerization reaction was completed for 1 hour.

After adding the antioxidant emulsion, it was coagulated with an aqueous potassium chloride solution and dried to obtain Polymer B-1.

Add 20n+j2 of toluene to 11g of Polymer B-24
After shaking for an hour, centrifugation (23,000 rpm)
) for 1 hour to remove the toluene-soluble portion.

The weight average molecular weight of this toluene soluble portion is 16.3×10
It was 4. [η] measured in toluene solution at 30°C was 0.60. Also, the toluene insoluble part accounts for 69% of the total.
Met.

Manufacture of Polymer B-2 1'J Name Wataru I + Suki・717 Screws 1 Ogome Exhaustion Volume 1 After sufficient substitution, 4000 g of diene rubber latex (particle size 0.23μ) (solid content ), 300 g of sodium dodecylbenzenesulfonate, 30 g of potassium hydroxide
After adding 6,000 g of styrene and 1,900 g of ion-exchanged water, the mixture was thoroughly stirred and heated while circulating hot water at 70°C through the jacket. When the internal temperature reached 50°C, an aqueous solution containing 950 g of ion-exchanged water, 20 g of sodium pyrophosphate, 25 g of glucose, and 0.4 g of ferrous sulfate and 35 g of cumene hydroperoxide were added, and a polymerization reaction was carried out for 2 hours. After that, after adding an aqueous solution consisting of 6.7 g of sodium pyrophosphate, 8.3 g of glucose, 0.13 g of ferrous sulfate, and 317 g of ion-exchanged water, and 7 g of cumene hydroperoxide, a polymerization reaction was carried out for 1 hour to complete the reaction. did.

After adding the antioxidant emulsion, it was coagulated with an aqueous potassium chloride solution and dried, and the toluene insoluble portion was 62% and the weight average molecular weight of the polystyrene portion was 33.7 x 104.
Polymer B-2 with η] of 1.0 was obtained.

Production of Polymer B-3 Under the production conditions of Polymer B-2, sodium pyrophosphate,
Polymerization was carried out using 75 g of potassium persulfate instead of glucose, ferrous sulfate, and cumene hydroperoxide. The weight average molecular weight of the polystyrene portion of the obtained polymer was 61 x 104, [η] was 1.6,
The toluene insoluble portion was 62% of the total.

Production of styrenic polymer (c) Under the production conditions of polymer B-2, polymerization was carried out using potassium persulfate as a polymerization initiator without using diene rubber latex, sodium birophosphate, glucose, or sulfuric acid. I did this.

Table 1 shows the amount of potassium persulfate used and the average molecular weight of the obtained polymer.

Table 1 After the inside of a stainless steel reaction vessel equipped with a stirrer was sufficiently purged with nitrogen, 10,000 g of styrene and 25 g of tertiary dodecyl mercaptan were charged and a polymerization reaction was carried out at 140°C. The average molecular weight of the obtained polymer was 57 x 10
It was 3.

Production of Polymer (Styrene-Acrylonitrile Copolymer) The following styrene-acrylonitrile copolymer was obtained by emulsion polymerization. Polymerization is carried out in three stages, with the first stage (
Charged styrene/acrylonitrile-33,5/24.3
(parts)) is batch polymerization, the second stage (charged styrene/acrylonitrile = 19.010.84 (parts)) is an incremental step, and the following is intermittent polymerization, and the third stage (charged styrene/acrylonitrile = 22.510. 76 (parts)) was carried out by incremental polymerization, and the polymerization was carried out until the final polymerization conversion rate was close to 100%.

The polymer was recovered by dipping into an aqueous solution of potassium chloride, and dried to obtain a polymer (D)). The polymer (D) is a polymer in which acrylonitrile has a composition distribution.

The toluene soluble portion of the obtained polymer was 52%, and the average molecular weight of the toluene soluble portion was 143 XIO''.

Cyclohexane is added little by little to a homogeneous solution in which a certain amount of the two-plate polymer is dissolved in methyl ethyl ketone, the precipitated polymer is separated at each stage, and the acrylonitrile content of the polymer is determined by nitrogen analysis. Ta. The results are shown in the table below.

Table-2 □□□〒 According to the composition ratios in Table-3, the various polymers were extruded into pellets using a twin-screw kneading extruder at >L degree of 260°C to 280°C, and then sufficiently dried. Test pieces for evaluating impact resistance, heat resistance, solvent resistance, and moldability were molded using an injection molding machine at a cylinder temperature of 280°C and a mold temperature of 50°C, and the results were measured according to the test method below. are shown in Table-2.

1/4" thickness according to ASTM 064B, 264
The heat distortion temperature was measured with PSi.

(2) Impact resistance Measured according to ASTM 0256 with a thickness of 1/4" and a notch.

(3) Processability of molded products Using a melt indexer manufactured by Takara Kogyo, JISK 721
0, cylinder temperature 280℃, load 10kg T
:MFI? (g/10mln) was measured.

(4) Solvent resistance A test piece with a thickness of I/8", a width of 1/2" and a length of 5"
% strain in kerosene, and the time until complete destruction was measured.

Further, Table 2 shows the mixture υ1 of component (c') and the average molecular weight measured by the above method.

Comparative Example-I is an example using only a styrene resin with a low molecular weight and has poor solvent resistance.

Comparative Example 2 is an example using only a styrene resin with a high molecular weight, and has poor processability.

Comparative Example 3 is an example in which a styrene polymer having a molecular weight in a low range outside the range of the present invention is used, and the solvent resistance is poor.

Comparative Examples to 4 are examples in which the amount of high molecular weight styrene resin is small, and the solvent resistance is poor.

As in Comparative Example-5, the average molecular weight of (c') is 32
If it is X 10' or more, the molding processability is greatly inferior.

In Comparative Examples 6 and 7, polyphenylene ether is outside the scope of the present invention, and the heat resistance is poor in the region where the polyphenylene ether is small, and the workability is poor in the region where the polyphenylene ether is large.

f0 Effects of the invention Conventionally, in compositions of polyphenylene ether and styrene resin, increasing the molecular weight of polystyrene improves solvent resistance, but on the other hand, processability decreases, making it difficult to mold. In this way, solvent resistance and processability are contradictory.

In contrast, the present invention improves this problem by mixing styrene resins with high and low average molecular weights in a specific ratio, and by using a mixture with a weight average molecular weight of 32 x 104 or less. A composition can be obtained that simultaneously improves moldability and solvent resistance, which are previously contradictory properties.

Claims (1)

[Claims] Contains (a) polyphenylene ether (b) a grafted rubber (a') grafted with a monomer whose main component is an aromatic vinyl compound and/or a non-grafted rubber (b') A composition comprising a styrene resin, comprising: (a) a toluene soluble portion in the styrene resin (b);
c') has a weight average molecular weight of 7 x 10^4 to 18 x 10^
4 polymer 5-95% by weight and weight average molecular weight 20×
Consisting of 95 to 5% by weight of a polymer of 10^4 or more,
and the weight average molecular weight of the mixture is 32 x 10^4 or less, (b) the content of the polyphenylene ether (a) in the composition is 95 to 5% by weight, and (a') and (b' ) has a total content of 2 to 50% by weight, and (
A polyphenylene ether resin composition characterized in that the content of c') is 93 to 3% by weight.